Manufacture of earthenware lavatories.



R. E. CRANE.

MANUFAGTURE 0F EARTHBNWARE LAVATORIES.

1 APPLICATION FILED DEG. 7, 1909.

Patented June .14, 1910.

(llll UNITED STATES PATENT OFFICE.

RAYMOND E. CRANE, OF CAMERON, WEST VIRGINIA.

MANUFACTURE OF EARTHENWARE LAVATORIES.

To all whom it may concern:

Be it known that I, RAYMOND E. CRANE, a citizen of the United States, and resident of Cameron, county of Marshall, and State of WVest Virginia, have invented certain new and useful Improvements in Manufacture of Earthenware Lavatories; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to the manufacture of earthenware lavatories, and more particularly to lavatories wherein a wall back is formed integral with the basin, usually by means of the integral slab that surrounds the latter. According to the usual method of making these articles, the basin and back are formed separately from soft sticky clay, by means of suitable molds or forms, and then stuck together, after which the piece is fired, dipped in the glaze, and then given a final firing. lVhen lavatories are made in this way, there is apt to be considerable distortion and warpage of the piece during firing, owing to the fact that it is of slight density and must of necessity undergo a marked shrinkage. Again, a piece of this kind has a tendency to fracture or come apart at the junction of the slab and back or at other points, this being usually due to the unequal density of the slab and back or nonuniform density of the clay in the slab or back, or both, and also to the strains that are incident to the usual method of manufacture and well understood in the art. Further, a marked disadvantage of this method is that two firings are necessitated, it being essential to fire the piece before it can be glazed (owing to the fact that it would otherwise crumble or fall apart on account of its softness) and then after glazing. When the piece is first fired there is considerable shrinkage to come out of it, and consequently thereis more or less warpage and distortion; and these latter results are also incident to the second firing.

The object of the present invention is to avoid these drawbacks. I aim to produce a simple and inexpensive method for shaping up or forming an earthenware lavatory of the type indicated, and while shaping the piece to prepare it for the firing process 1n Specification of Letters Patent.

Application filed December 7, 1909.

Patented June 14, 1910. Serial No. 531,892.

such a manner that there will be less risk of warpage and the unsymmetry common in fixtures of this class. It is also aimed to prevent any tendency to break or fracture in particular, at the junction of the back and slab and to give the piece such density that if it is to be glazed it can be dipped in the glaze without a preliminary firing, thus doing away with one firing and simplifying considerably the manufacture of the lavatory.

The improved method will be described by reference to the accompanying drawing, in which the single View is a sectional perspective of a mold adapted for use in carrying out the invention.

In the drawing, the mold is shown as constituted by a lower female member or die A and an upper male member or die B. The die A is cut out to form the lower surface of the lavatory G that is to be molded, the upper die 13 being provided with a depending projection 19 to enter the clay chamber of the lower die and thereby mold into shape between the opposing surfaces, the back a, basin 0, and slab c of the lavatory. The mold chamber is formed to receive entirely both the back and basin, and it will be noted that the lavatory is preferably inclined with respect to the lower die, the top of the back and the front of the basin rim being located in approximately the same horizontal plane. This causes the angle or apex a between the back forming surface of the lower die and the basin-forming depression thereof, to be located comparatively far down in the lower die, viz., in the bottom of the mould. Opposite the angle or apex a, the male die is provided with a corresponding ridge 6 which fits into said angle to mold the piece at the junction of the back and slab. The male die B is composed of laterally separated sections 6 between which is interposed a wedge D, the downward movement of which moves the sections horizontally and away from each other. The sections are normally held together and prevented from such a movement by means of a suitable device such as a detachable clamping ring or collar 6 that may be removed when the upper die is supported on the lower die, as will hereinafter appear. The upper die is provided with a circular series of u right channels or openings 7) for Y the introc uction of clay into the mold chamber and similar channels at are cut in the wedge D. The lower die A is provided with channels a leading to the mold chamber and serving to introduce compressed air to aid in freeing the molded lavatory from said die.

\Vith a mold of the construction described, my improved process is carried out as follows: I first form a suitable mixture of pulverized clay preferably containing relatively little moisture, viz., wherein the particles will not cohere except under heavy pressure, the clay presenting the appearance of a dry powder. This clay mixture is placed in the lower die A and roughly shaped up by suitable manual manipulation, to present the general shape that is to be given to the lavatory C; the basin part 0, wall back 0 and slab c are formed in a continuous mass of pulverized clay which lies in a layer of the requisite dept-h over the molding surface of the lower die. This preliminary shaping may, however, be omitted in some instances. The upper die is then placed over the lower die so that the under surface of the former will lie on the roughly formed clay, the ring 6 holding together the sections of the upper die when the latter is moved into the position indicated and while it is in that position. The mold is then placed in a suitable power press and a relatively light vertical pressure imposed upon the die sections Z2 which will increase the density of the clay to a certain extent and give it a closer approximation of the final shape. During this step the wedge D is inactive, merely resting between the die sections 12 and having no vertical movement, due to the fact that no pressure is exerted on it and that the ring 6 prevents the separation of the sections. After this preliminary forming of the clay has been effected, it will usually be found that a part of the clay in the higher portions of the lower die has been forced downward to a certain extent, into the lower part of the die, owing to the downward pressure of the upper die and the inclination of the molding surfaces, with the result that the clay will be unequally distributed. The higher parts of the piece will be less thick and also less dense. In order to avoid such a result in the finished piece, I introduce at this stage an additional quantity of clay into the mold chamber, which clay is suitably applied to and worked into the upper part of the piece at the points where it is needed. This may be effected by raising the upper die away from the lower die, on which it rests, and placing more clay of the same kind on the upper surface of the piece, and such clay may, for example, be in the form of small compressed cakes. However, I prefer to introduce the additional clay in the form of a powder through the channels or openings 5 in the upper die, which has the advantage that the latter does not have to be lifted from its seat on the lower die at this stage of the operation. In this way the density of the piece can be made uniform.

When the lavatory has been partly formed, as indicated, the ring or collar 6 is removed from the die sections 6 and the power press is caused to act on the upper end of the wedge D, the sections 6 being maintained in the same horizontal plane as before. This results in an extremely heavy lateral pressure on the piece, from the center toward the front and back thereof, through the intermediacy of the laterally moving die sections. The press acts on the wedge with a considerably greater pressure than the vertical pressure first exerted, and a greater and more uniform density is obtained throughout the back of the lavatory and the more diflicult parts of the basin. The particles of clay are thereby caused to cohere strongly, and the article is given the strength and rigidity necessary to enable it to undergo the final steps of the process. As the wedge descends, powdered clay is introduced through its channels (Z, and this is heavily compressed in the basin part by the vertically acting lower end of the wedge, so that uniformity and high density of the clay throughout the entire piece is produced. When this final pressure has been completed, the lavatory is removed from the mold by raising the upper die and blowing compressed air through the channels a, between the lower surface of the clay and the upper surface of the lower die, whereby the piece is freed from the latter so that it can be lifted out of the same. If it is desired to glaze the piece, it is then ready for that operation, without any preliminary firing, because it is of great density and strength and will not crumble under the action of the wet glaze in which it is dipped. Or, of course, the glaze can be applied with a brush. The fiuxes used in the composition of the glaze are of a special nature so that the melting point of the latter will have such a relation to the firing temperature that firing can take place after the glaze has dried. After glazing, firing is effected in the usual way, and it will be found that the great density and uniformity of the article will prevent any warpage or distortion during this operation. Ordinarily two firings are necessitated, and the first firing takes place when the ware is soft and has much shrinkage to come out of it, with distortion resulting in both firings; but this disadvantage is to a very great extent overcome by the present method. A further advantage arises from the fact that great and uniform density is obtained at the various angles and corners of the ware, so that unequal shrinkage and consequent fracture and warpage in the firing are avoided. When the density is not uniform such fracture and warpage are bound to occur when the ware is, as usual, fired to such an extent that the clay is melted and becomes Vitreous or glassy, shrinking sometimes as much as one and one half inches to the foot under actual working conditions. It is therefore highly essential to provide for the even distribution of the clay in the mold in the manner indicated.

By locating the angle of junction between the back and slab low down in the mold, a greater and more uniform pressure can be obtained, and there will be less dislocation of clay in the back than would be the case if the back were placed vertically, as will be manifest. Should the clay be strained at the junction of the slab and back, as is usually the case in the ordinary method of makin earthenware lavatories, the press is power ul enough to knit the parts together, and after firing, the entire piece will be a harmonious and homogeneous unit of great strength and symmetry.

I am aware that prior to my invention porcelain articles of various kinds have been made by stamping, but I know of no instance where such a complex piece as a lavatory with an integral wall back has been made by a method similar to that herein described, nor of any instance where the problems arising from the stamping and firing of such a diflicult piece have been successfully solved. Under these circumstances I do not wish to limit myself to the precise steps described, nor to the use of any particular apparatus, as it is impossible to describe the various modifications that can be adopted without digressing from the inventive idea involved.

What I claim is 1. The method of manufacturing earthenware lavatories having integral wall backs, which comprises placing in a suitable mold sufficient clay to form the basin and back, with the junction of the back and basin located in a deepened part of the mold for forming the outside of the lavatory, the latter being placed for this purpose in an inclined position with respect to the mold, and heavily compressing the clay throughout the entire piece by forcing a compressing element against the clay, whereby a high and uniform density is given to the lavatory; substantially as described.

2. The method of manufacturing earthenware lavatories having integral wall backs, which comprises placing in a suitable mold the clay to form the basin and back as an integral whole, with the junction of the back and basin in a deepened part of the mold, to form the outside of the lavatory, the latter being placed for this purpose in a plane at an angle to that of the mold, then giving the piece a slight initial pressure by forcing a compressing element against the clay in the mold, and exerting a separate and heavier pressure on said element and against the clay to give the latter a high and uniform density; substantially as described.

3. The method of manufacturing earthenware lavatories having integral wall backs, which consists in roughly shaping the clay piece as a whole in a suitable mold, then shaping the piece by the application of heavy pressure suflicient to give the same high density and hardness, dipping the piece in the glaze after its removal from the mold, with the back integral therewith, and without preliminary firing, and then firing the lavatory thus formed; substantially as described.

l. The method of manufacturing earthenware lavatories having integral wall backs, which comprises placing in a suitable mold sufficient dry pulverized clay to form the basin and back, roughly shaping the piece as an integral whole, forming it by a relatively slight initial pressure, adding clay to the piece at the portions thereof where the initial pressure has caused a lack of uniformity and density therein, and then giving the piece a heavy final pressure suflicient to cause a strong coherence of the clay particles and a high density of the article; substantially as described.

5; The method of manufacturing earthenware lavatories, which comprises placing in a suitable mold sufiicient dry pulverized clay to form the lavatory, roughly shaping the piece into an integral unit, giving it a relatively slight vertlcal pressure to form the same, adding clay at those points where such pressure has caused a lack of uniformity and density, and then giving the piece a heavy lateral pressure sufficient to cause a strong coherence of the clay particles and a high density throughout the lavatory; substantially as described.

6. The method of manufacturing earthenware lavatories having integral wall backs, which comprises placing in 'a suitable mold suflicient clay to form the basin and back, roughly shaping the lavatory as a unit in the mold, with the junction of the back and basin located in the lower part of the latter, the lavatory being placed for this purpose in inclined position with respect to the mold, and heavily compressing the clay throughout the entire piece, to produce a high and uniform density throughout the lavatory; substantially as described.

7. The method of manufacturing earthenware lavatories having integral wall backs, which comprises introducing into a mold suflicient dried pulverized clay to form the basin and back of the lavatory, roughly shaping the piece as an integral whole in which the basin and back are combined,

compressing the clay in the mold in both the In testimony whereof affix my signature, basin and back at such a pressure as to in presence of tWo Witnesses.

cause the clay particles to cohere strongly and form a unit of high density and hard- RAYMOND CRANE ness, removing the piece from the mold, and Witnesses:

finally glazing and. firing the same; snbstan- CHAS. T. SCHWARZ, tially as described. G. E. WALBERT. 

